JPH02251554A - Vinyl chloride-based resin composition - Google Patents

Abstract

PURPOSE:To obtain a composition suitable for various weak electrical appliances having excellent resistance to heat distortion, resistance to impact and fluidity in processing, etc., by mixing specific vinyl chloride-based copolymer and specific copolymer, etc., comprising vinyl cyanide, etc., in specific ratio. CONSTITUTION:(A) 15 to 80wt.% vinyl chloride-based copolymer containing A1: 50 to 99wt.% constructing unit derived from vinyl chloride and 50 to 1wt.% constructing unit derived from N-substituted maleimide expressed by formula I [R is 1 to 30C group such as (substituted) aliphatic, etc.; R' and R'' are H or fluorine, etc.] and having 400 to 1000 average degree of polymerization is mixed with (B) 15 to 80wt.% copolymer obtained by polymerization of monomer mixture composed of at least two of vinyl cyanide compound and aromatic vinyl compound, etc., and (C) 5 to 40wt.% graft copolymer composed of C1: 40 to 95 pts.wt. rubbery polymer polymerized with C2: 60 to 5 pts.wt. monomer mixture composed of at least two of vinyl cyanide compound, etc., to afford the objective composition.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a vinyl chloride resin composition, and more specifically, the present invention relates to a vinyl chloride resin composition, and more specifically, it has excellent heat deformation resistance and impact resistance of molded products, as well as fluidity and thermal stability during molding. The present invention relates to a vinyl chloride resin composition with excellent properties.

[Prior art and problems] As a method for improving heat deformation resistance, SII resistance, etc. of vinyl chloride resin, a polymer obtained by grafting a vinyl cyanide compound, an aromatic vinyl compound, an alkyl acrylate, an alkyl methacrylate, etc. to rubber is used. A method of blending is known. Although this method improves heat deformation resistance and impact resistance, it cannot be said that the fluidity during molding, thermal stability, etc. are necessarily satisfactory, and the heat deformation resistance temperature has also been increasing in recent years. Therefore, as an aromatic vinyl compound, we are using α-methylstyrene monomer, which can be expected to have a higher heat distortion temperature, or increasing its content, or even using aromatic vinyl compounds with a higher heat distortion temperature. A number of improvement methods have been attempted, such as increasing the proportion of graft copolymers used, but on the other hand, these methods drastically reduce fluidity during molding and significantly reduce the impact strength of molded products. There are some practical problems such as lowering the performance.

[Means for solving problems]

In view of the above circumstances, the inventors of the present invention have conducted intensive studies on a vinyl chloride resin composition that has excellent heat deformation resistance and impact resistance for molded products, as well as excellent fluidity and thermal stability during molding. This invention has been achieved.

That is, the present invention comprises 50 to 50 structural units derived from vinyl chloride.
99% by weight, and - maximum (1) (wherein R is a substituted or unsubstituted aliphatic, alicyclic or aromatic group having 1 to 30 carbon atoms, and R' and R'' are 50 to 1% by weight of structural units derived from N-substituted maleimides, which may be the same or different and are hydrogen, fluorine, chlorine, or bromine atoms, cyanide groups, or alkyl groups having 3 or less carbon atoms. and has an average degree of polymerization (JIS K6721) of 4.
00-1000 vinyl chloride copolymer (A) 15-8
0% by weight, 15 to 80% by weight of a copolymer (B) obtained by polymerizing a monomer mixture consisting of at least two of a vinyl cyanide compound, an aromatic vinyl compound, and an alkyl acrylate or an alkyl methacrylate, and rubber. A graft copolymer obtained by polymerizing 60 to 5 parts by weight of a monomer mixture consisting of at least two of a vinyl cyanide compound, an aromatic vinyl compound, and an alkyl acrylate or an alkyl methacrylate to 40 to 95 parts by weight of a polymer. (
C) A novel product consisting of a vinyl chloride resin composition containing 5 to 40% by weight, which provides molded products with excellent heat deformation resistance and impact resistance, as well as excellent fluidity and thermal stability during molding. It contains a vinyl chloride resin composition.

The vinyl chloride copolymer (A) used in the present invention has a constitutional unit derived from vinyl chloride in an amount of 50 to 99% by weight, preferably 70 to 99% by weight, and the N- The structural unit derived from substituted maleimide accounts for 50 to 1% by weight, preferably 30 to 1% by weight, and the average degree of polymerization is 4.
00-1000 vinyl chloride copolymer. If the content of the structural unit derived from N-substituted maleimide is less than 1% by weight, the heat deformation resistance of the copolymer will be insufficiently improved, and the heat deformation resistance of the composition will also be insufficient.
If the amount exceeds % by weight, the melt viscosity of the copolymer becomes too high, resulting in poor moldability of the composition. In addition, when the degree of polymerization of this copolymer is lower than 400, the impact resistance of the composition is extremely low, and when the degree of polymerization exceeds 1000, the melt viscosity of the composition becomes too high, resulting in a significant decrease in moldability. do.

-m Specific examples of the N-substituted maleimide represented by formula (1) include N-methylmaleimide, N-ethylmaleimide, N-n-propylmaleimide, N-isopropylmaleimide, N-n-butylmaleimide, N- -tert,
-Butylmaleimide, N-hexylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-
(p, m.

0)-Hydroxyphenylmaleimide, N-(p.

m,0)-methoxyphenylmaleimide, N-(p,m
, o)-chlorophenylmaleimide, N(p,m,o)
-carboxyphenylmaleimide, N-(p, m, o)
-Nitrophenylmaleimide and the like.

In addition, in the production of the vinyl chloride-based copolymer (A), it is possible to use other polymerizable monomers and a small amount of a polymer that can be graft-polymerized with vinyl chloride (both of which can be used as a raw material), if necessary. can.

Other polymerizable monomers include vinyl esters such as vinyl acetate, vinyl caproate, vinyl laurate, and vinyl stearate, olefins such as ethylene, propylene, and isobutylene, isobutyl vinyl ether, octyl vinyl ether, dodecyl vinyl ether, and phenyl. Alkyl vinyl ethers such as vinyl ether, halogenated olefins such as vinylidene chloride, vinyl fluoride, propylene chloride, vinyl bromide, ethyl acrylate, n-butyl acrylate, n-butyl methacrylate, 2-ethylhexyl acrylate, 2-ethyl Examples include acrylic acid and methacrylic esters such as hexyl methacrylate and stearyl methacrylate, acrylic derivatives such as acrylic acid, methacrylic acid, crotonic acid, acrylonitrile, maleic anhydride, and itaconic anhydride. These are not limited to one type, and two or more types may be used simultaneously.

In addition, as polymers that can be graft-polymerized with vinyl chloride,
Ethylene-vinyl acetate copolymer (Eν^), ethylene-
Ethyl acrylate copolymer, chlorinated polyethylene, polyurethane, polybutadiene-styrene-methyl methacrylate (MBS), polybutadiene-acrylonitrile-(α-methyl)styrene (8BS), polybutyl acrylate, butyl rubber, polystyrene, styrene-butadiene copolymer Examples include polymers and crosslinked acrylic rubber.

The above-mentioned other polymerizable monomers and polymers contain 30% by weight of the constituent parts derived therefrom in the resulting copolymer.
It is preferable to use it in an amount less than 15% by weight, and more preferably 15% by weight or less.
That is, high mechanical strength, durability, etc. are lost.

The vinyl chloride copolymer (A) can be obtained by any method such as bulk polymerization, suspension polymerization, or emulsion polymerization, but suspension polymerization is generally used industrially. ,
Economically advantageous.

As the free radical-generating polymerization initiator used in the polymerization, those commonly used in the polymerization of vinyl chloride can be used, such as decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, di(isopropyl) peroxy Diacyl peroxides such as dicarbonate, di(2-ethylhexyl) peroxycarbonate, acetylcyclohexylsulfonyl peroxide, te'', -butylperoxyvivalate, tert, -butylperoxyneodecanate, etc. Organic peroxides of esters, and α,α-azobisisobutyronitrile, α,α′-azobis2.4
-dimethylvaleronitrile, α.

Examples include azo compounds such as α'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and water-soluble peroxides such as potassium persulfate and ammonium persulfate.
The species can be used alone or in combination of two or more species.

“As the polymerization method, the suspension polymerization method is preferable as described above, but the suspension stabilizers used in that case may be those normally used in the polymerization of vinyl chloride monomers, such as suspension polymerization. Examples of turbidity stabilizers include fully saponified or partially saponified polyvinyl alcohol, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, polyvinylpyrrolidone, and synthetic polymer compounds such as maleic anhydride-vinyl acetate copolymer. Examples include natural polymeric substances such as , starch, and gelatin.
These are not limited to one type, and two or more types may be used in combination.

After polymerization, the vinyl chloride copolymer (A) is dehydrated and dried to obtain a powder.

The copolymer (B) used in the present invention is a copolymer obtained by polymerizing a monomer mixture consisting of at least two of a vinyl cyanide compound, an aromatic vinyl compound, and an alkyl acrylate or an alkyl methacrylate, and further Specifically, it is a copolymer obtained by polymerizing a monomer mixture of 10 to 40% by weight of a vinyl cyanide compound, 60 to 90% by weight of an aromatic vinyl compound, and 0 to 20% by weight of an alkyl acrylate or alkyl methacrylate. The intrinsic viscosity of the dissolved part in dimethylformamide solution is
0.25~0.70dj at 80℃! In the copolymer (B), which is preferably in the range of /g, if the vinyl cyanide compound exceeds 40% by weight, the fluidity during molding of the vinyl chloride resin composition of the present invention decreases. 10
If the amount is less than % by weight, the impact resistance etc. of the molded product will decrease. If the amount of the aromatic vinyl compound is less than 60% by weight, the fluidity of the composition during molding will decrease, and if it exceeds 90% by weight, the impact resistance of the molded product will decrease. The intrinsic viscosity of the methyl ethyl ketone soluble portion of copolymer (B) in dimethyl formamide solution is 0.2
It is preferable that the intrinsic viscosity is from 5 to 0.70 dl/g.If the intrinsic viscosity is less than 0.25, the impact resistance of the molded product will decrease;
If it exceeds 70, the fluidity of the composition during molding will decrease and the thermal stability will also decrease.

Examples of vinyl cyanide compounds in the copolymer (B) include acrylonitrile and methacrylonitrile; examples of aromatic vinyl compounds include styrene, α-methylstyrene, methylstyrene, and chlorostyrene; alkyl acrylates and alkyl styrenes; Examples of methacrylate include ethyl acrylate, butyl acrylate, methyl methacrylate, and ethyl methacrylate.

The graft copolymer (C) used in the present invention is a monomer mixture consisting of 40 to 95 parts by weight of a rubbery polymer, a vinyl cyanide compound, an aromatic vinyl compound, and at least two of alkyl acrylate or alkyl methacrylate. It is a graft copolymer obtained by polymerizing ~5 parts by weight. In the graft copolymer (C), the rubbery polymer is 4
If it is less than 0 parts by weight, the impact resistance of the molded product will decrease, and if it exceeds 95 parts by weight, the fluidity during molding will decrease, which is not preferable.

Examples of the rubbery polymer in the graft copolymer (C) include diene rubbers such as polybutadiene rubber, styrene-butadiene copolymer rubber (SBR), acrylonitrile-butadiene rubber (NBR), and polybutyl acrylate. acrylic rubber such as, and ethylene-propylene
Examples include polyolefin rubbers such as diene terpolymer rubber (flPDM). Examples of vinyl cyanide compounds include acrylonitrile and methacrylonitrile; examples of aromatic vinyl compounds include styrene, α-methylstyrene, methylstyrene, and chlorostyrene; examples of alkyl acrylates and alkyl methacrylates include ethyl acrylate and butyl acrylate. , methyl methacrylate, ethyl methacrylate and the like.

The content of the vinyl chloride copolymer (A) in the vinyl chloride resin composition of the present invention is 15 to 80% by weight;
If it is less than 80% by weight, the weather resistance and flame retardance of the molded article will be reduced, and if it exceeds 80% by weight, the fluidity during molding will be reduced. Further, the content of the copolymer (B) is 15 to 80% by weight,
If this is less than 15% by weight, the fluidity during molding will decrease, and the
If it exceeds 0% by weight, the weathering resistance and flame retardancy of the molded article will decrease. Furthermore, the content of the graft copolymer (C) is 5 to 40% by weight; if it is less than 5% by weight, the impact resistance of the molded product will decrease, and if it exceeds 40% by weight, the fluidity during molding will decrease. do. Copolymer (B) and graft copolymer (
A known emulsion polymerization method can be applied to the polymerization of C), and in that case,
After completion of the hexapolymerization, a known polymerization initiator, polymerization degree regulator, etc. can be appropriately used by a known method, and the desired powder can be obtained by coagulating the latex by a known method. The copolymer (B) and the graft copolymer (C) may be blended in a latex state, or may be coagulated and then blended in a powder state.

The vinyl chloride resin composition of the present invention is obtained by blending a predetermined amount of a vinyl chloride copolymer (A) powder with predetermined amounts of each of a copolymer (B) and a graft copolymer (C). 0 The vinyl chloride resin composition of the present invention may contain not only known antioxidants, heat stabilizers, and lubricants, but also UV absorbers, pigments, antistatic agents, flame retardants, flame retardant aids, etc. as necessary. Can be used together.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples, but these Examples do not limit the present invention. In Examples and Comparative Examples, "parts" are parts by weight, and "%" is Indicates weight %.

(a) Preparation of vinyl chloride copolymer (A) The following materials were charged into a pressure-resistant reaction vessel equipped with a stirrer and a cooler.

Water 200 parts Partially saponified polyvinyl alcohol 0.2 parts (degree of saponification 80 mol%, average degree of polymerization 2400) tart, -Butyl peroxyneodecanate Specified amount shown in Table 1 3.5.5-) Limethylhexanoyl Peroxy, de N-cyclohexylmaleimide or N-phenylmaleimide in the specified amount shown in Table 1 After degassing the reaction vessel, vinyl chloride is converted into N-cyclohexylmaleimide or N-phenyl in the specified amount shown in Table 1. A total of 100 parts including maleimide was added, and polymerization was carried out at a predetermined polymerization temperature with stirring until a polymerization conversion rate of 80 to 85% was reached.

Unreacted vinyl chloride was collected, and the slurry was dehydrated and dried by a conventional method to obtain a white powder polymer.

Table 1 shows the composition and degree of polymerization of the obtained polymer.

(b) Preparation of copolymer (B) The following substances were charged into a reaction vessel equipped with a stirrer and a cooler.

Water 250 parts Sodium formaldehyde sulfoxylate 0.4 parts Ferrous sulfate 0.0025 parts Disodium ethylenediaminetetraacetate 0.01 parts Sodium laurate 1.5 parts After degassing the reaction vessel, under stirring in a nitrogen stream A monomer mixture of 26 parts of acrylonitrile, 24 parts of styrene, and 50 parts of α-methylstyrene, a polymerization initiator cumene hydroperoxide, and a polymerization degree regulator tert,-dodecyl mercaptan were heated to 60°C for 5 hours. 0 added dropwise continuously
After the dropwise addition was completed, stirring was further continued at 60° C. for 1 hour to complete the polymerization. A phenolic antioxidant was added to the obtained latex of the polymer, which was coagulated with an aqueous calcium chloride solution, washed with water, dehydrated, and dried to obtain a powder of copolymer (B). The intrinsic viscosity of the methyl ethyl ketone soluble portion of this polymer was 0.40 dl/g.

(c) Preparation of graft copolymer (C) A reaction vessel equipped with a stirrer and a cooler was charged with the following substances and the rubbery polymer shown in Table 2.

Water 250 parts Sodium formaldehyde sulfoxylate 0.2 parts Ferrous sulfate 0.0025 parts Ethylenediaminetetraacetic acid disodium 0.01 parts Polybutadiene Predetermined amounts shown in Table 2 After degassing the reaction vessel, stir in a nitrogen stream. The mixture was heated to 60°C, and the monomer mixture in the proportions shown in Table 2 and the polymerization initiator cumene hydroperoxide were continuously added dropwise over 5 hours. After the completion of the dropwise addition, the mixture was further heated to 60°C for 1 hour. Stirring was continued to complete the polymerization. A phenolic antioxidant was added to the obtained latex of the polymer, which was coagulated with an aqueous calcium chloride solution, washed with water, dehydrated, and dried to obtain a powder of the graft copolymer (C).

(d) Molding of vinyl chloride resin composition The vinyl chloride copolymer (A), copolymer (B), and graft copolymer (C) prepared in (a), (b), and (c) above ) to obtain a resin composition, to which a tin stabilizer, a lubricant and a pigment were added and blended in a super mixer, and then pellets were produced in a 40 m/m extruder. As a tin stabilizer, 2 parts of dibutyltin malate,
and 1 part of dibutyltin mercapto, 1 part of glycerin tristearate and 1 part of polyethylene wax as lubricants, and 1 part of titanium oxide as pigment. A test piece was molded from this pellet using a 5-ounce injection molding machine under conditions of a screw speed of 8 rpm and a nozzle temperature setting of 200°C.

(E) Evaluation ■Heat resistance is based on ASTM D 256, l8.
Evaluation was made at the heat distortion temperature at a load of 6 kg/Cj.

(2) Impact resistance was evaluated by an Izot impact test based on ASTM D 64B.

(2) Fluidity was evaluated using Koka Type B method flow at a temperature of 190° C. and a load of 150 kg/cj.

■Thermal stability was evaluated by the degree of discoloration of the resin remaining in the nozzle of the molding machine after molding. Evaluation was made using a 5-point system, with the maximum being 5 points and the minimum being 1 point. The larger the number, the better the thermal stability.

(2) Weather resistance was evaluated using a xenon lamp at a black panel temperature of 55° C. for 800 hours, and the degree of discoloration at that time was evaluated as follows.

O: Good Δ: Slightly inferior ×: Inferior (2) Flame retardancy was evaluated based on the UL-94 standard.

The evaluation results are shown in Table 3.

〔Effect of the invention〕

The vinyl chloride resin composition of the present invention can be used as a flame retardant material that has excellent heat deformation resistance and impact resistance for molded products, as well as excellent fluidity and thermal stability during molding. It can be suitably used for exterior materials and members that require heat resistance such as around heat sources and circuits.

Claims (1)

[Claims] 1. 50 to 99% by weight of structural units derived from vinyl chloride;
and general formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼(I) (In the formula, R is a substituted or unsubstituted aliphatic, alicyclic or aromatic group having 1 to 30 carbon atoms. Yes, R' and R
'' may be the same or different and is a hydrogen, fluorine, chlorine or bromine atom, a cyan group, or an alkyl group having 3 or less carbon atoms.) 50 structural units derived from N-substituted maleimide represented by
~1% by weight of a vinyl chloride copolymer (A) having an average degree of polymerization of 400 to 1000, at least 15 to 80% by weight, a vinyl cyanide compound, an aromatic vinyl compound, and an alkyl acrylate or an alkyl methacrylate. A copolymer formed by polymerizing a monomer mixture consisting of two types (
B) 15-80% by weight and 60-5% by weight of a monomer mixture comprising at least two of vinyl cyanide compounds, aromatic vinyl compounds, and alkyl acrylates or alkyl methacrylates in 40-95 parts by weight of a rubbery polymer. A vinyl chloride resin composition comprising 5 to 40% by weight of a graft copolymer (C) obtained by polymerizing a portion of the graft copolymer (C).